A5032531605- Thin-Film Transistor Technologies
- Semiconductor materials and devices
- Silicon and Solar Cell Technologies
- Transition Metal Oxide Nanomaterials
- ZnO doping and properties
- Silicon Nanostructures and Photoluminescence
- Gas Sensing Nanomaterials and Sensors
- Advanced Memory and Neural Computing
- Plasma Diagnostics and Applications
- 2D Materials and Applications
- Electronic and Structural Properties of Oxides
- Copper Interconnects and Reliability
- Chalcogenide Semiconductor Thin Films
- Metal and Thin Film Mechanics
- Nanowire Synthesis and Applications
- Semiconductor materials and interfaces
- Quantum Dots Synthesis And Properties
- Ga2O3 and related materials
- Organic Electronics and Photovoltaics
- Graphene research and applications
- Copper-based nanomaterials and applications
- Optical Coatings and Gratings
- MXene and MAX Phase Materials
- Perovskite Materials and Applications
- Luminescence Properties of Advanced Materials
Korea Research Institute of Chemical Technology
2025
Electronics and Telecommunications Research Institute
2014-2024
Suzhou Research Institute
2023
Seoul National University
2022
Korea University of Science and Technology
2012-2021
Korea University
2008-2021
Government of the Republic of Korea
2018
University of Science and Technology
2017
Chang'an University
2013
Hebei GEO University
2012
Electrons in correlated insulators are prevented from conducting by Coulomb repulsion between them. When an insulator-to-metal transition is induced a insulator doping or heating, the resulting state can be radically different that characterized free electrons conventional metals. We report on electronic properties of prototypical vanadium dioxide which metallic increasing temperature. Scanning near-field infrared microscopy allows us to directly image nanoscale puddles appear at onset...
In femtosecond pump-probe measurements, the appearance of coherent phonon oscillations at 4.5 and 6.0 THz indicating rutile metal phase VO2 does not occur simultaneously with first-order metal-insulator transition (MIT) near 68 degrees C. The monoclinic correlated (MCM) between MIT structural (SPT) is generated by a photoassisted hole excitation, which evidence Mott transition. SPT MCM occurs due to subsequent Joule heating. can be regarded as an intermediate nonequilibrium state.
The optical and infrared properties of films vanadium dioxide $(\mathrm{V}{\mathrm{O}}_{2})$ sesquioxide $({\mathrm{V}}_{2}{\mathrm{O}}_{3})$ have been investigated via ellipsometry near-normal incidence reflectance measurements from far to ultraviolet frequencies. Significant changes occur in the conductivity both $\mathrm{V}{\mathrm{O}}_{2}$ ${\mathrm{V}}_{2}{\mathrm{O}}_{3}$ across metal-insulator transitions at least up (and possibly beyond) $6\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$. We...
For VO2-based two-terminal devices, the first-order metal-insulator transition (MIT, jump) is controlled by an applied voltage and temperature, intermediate monoclinic metal phase between MIT structural (SPT) observed. The conductivity of this linearly increases with increasing temperature up to TSPT≈68°C becomes maximum at TSPT. Optical microscopic observation reveals absence a local current path in phase. uniformly flows throughout surface VO2 film when occurs. This device can be used as...
We present a detailed infrared study of the insulator-to-metal transition (IMT) in vanadium dioxide $({\text{VO}}_{2})$ thin films. Conventional spectroscopy was employed to investigate IMT far field. Scanning near-field microscopy directly revealed percolative with increasing temperature. confirmed that phase is also cooling across IMT. extensive images coexistence regime ${\text{VO}}_{2}$. find coexisting insulating and metallic regions at fixed temperature are static on time scale our...
The most effective method, BD-method (combination of blending and dipping), is reported for increasing the conductivity PEDOT:PSS using sodium dodecyl sulfate Joule heating behaviour fabric heater demonstrated.
A room‐temperature HNO 3 treatment method is developed that significantly enhances the conductivity of a poly(3,4‐ethylenedioxythiophene):poly(4‐styrenesulfonate) (PEDOT:PSS) film, which one most promising transparent conducting materials. The PEDOT:PSS film treated with exhibits as high 4100 S cm −1 , highest value among reported conductivities achieved by treatments at room temperature. mechanism this enhancement elucidated means electrical, optical, structural, and compositional...
Molybdenum disulfide (MoS2) based field effect transistors (FETs) are of considerable interest in electronic and opto-electronic applications but often have large hysteresis threshold voltage instabilities. In this study, by using advanced transfer techniques, hexagonal boron nitride (hBN) encapsulated FETs on a single, homogeneous atomic-thin MoS2 flake fabricated hBN SiO2 substrates. This allows for better precise comparison between the charge traps at semiconductor-dielectric interfaces...
Objective: The objective of this paper is to explore, from a social worker's perspective, how older adults can utilize biological, psychological, and strategies enhance their subjective well-being in sustainable community setting. Theoretical Framework: Utilizing the Biopsychosocial Model, enhancing persons through interventions. Methods: study was conducted heavily aging community, using focus group interviews with six workers, each more than two years professional experience. Results...
In order to clarify whether ${\text{VO}}_{2}$ is a Mott insulator or Peierls insulator, the metal-insulator transition (MIT) and structural phase (SPT) are simultaneously monitored for films by current-voltage curve diffraction measurements using synchrotron micro-x-ray beam. regime showing metallic conductivity below SPT temperature (approximately $70\text{ }\ifmmode^\circ\else\textdegree\fi{}\text{C}$), only planes of monoclinic structure observed, while tetragonal absent. This observation...
In this letter, we report an observation of room temperature electrical oscillation in vanadium dioxide (VO2), a representative strongly correlated material showing metal-insulator transition. An electric circuit for the is simply composed voltage source and two-terminal VO2 thin film device serially connected with standard resistor. The systematic procedures where occurred were explained based on relationship between resistor, generation window was determined. particular, frequency could be...
An ambipolar dual-channel field-effect transistor (FET) with a WSe2 /MoS2 heterostructure formed by separately controlled individual channel layers is demonstrated. The FET shows switchable behavior independent carrier transport of electrons and holes in the MoS2 , respectively. Moreover, photoresponse studied at heterointerface FET.
Two-dimensional transition metal dichalcogenides (TMDCs) have emerged as promising materials for next-generation electronics due to their excellent semiconducting properties. However, high contact resistance at the metal-TMDC interface plagues realization of high-performance devices. Here, an effective metal-interlayer-semiconductor (MIS) is demonstrated, wherein ultrathin ZnO interlayer inserted between electrode and MoS2, providing damage-free clean interfaces electrical contacts. Using...
With the development of Internet Things (IoT), indoor photovoltaics are attracting considerable interest owing to their potential benefit various IoT-related fields. Therefore, this study investigates use transparent hydrogenated amorphous silicon (a-Si:H) solar cells for a broad range applications, including light harvesting. High-gap triple layers were employed in a-Si:H obtain high shunt resistance and short-circuit current, JSC, open-circuit voltage, VOC, under illumination....
The materials characteristics of Al2O3 films grown on a Si (100) substrate by traveling wave reactor atomic layer deposition were investigated in the growth temperature ranging from 250 to 500 °C. using Al(CH3)3 trimethylaluminum (TMA) and H2O as precursors characterized also compared with AlCl3 H2O. Both samples different revealed identical chemical binding state oxidized Al very flat surface morphology. In study impurity incorporation, TMA showed C H count rates secondary ion mass...
The passivation of organic light-emitting diodes (OLEDs) with Al2O3 films containing small amounts N (Al2O3:N) was investigated by plasma-enhanced atomic layer deposition using a direct rf plasma short pulse time. Luminance—voltage and current density—voltage curves an OLED passivated 300nm Al2O3:N film at 60°C remained unchanged compared to those nonpassivated 96% the initial luminance were maintained even after operating for 850h 14mA∕cm2. lifetime 80°C 650h, 6.2 times longer than that...
Plasma-enhanced atomic layer deposition (PEALD) technique using trimethylaluminum (TMA) precursors and gas mixed with gas, was adopted as a promising method for growing thin films improved electrical properties compared to the conventional ALD. PEALD provides higher growth rate of 0.18 nm/cycle than ALD does 0.11 at 100°C. Due superior film density that ALD, excellent breakdown fields 9 MV/cm were obtained in The dielectric constants grown by also produced © 2004 Electrochemical Society. All...
In the solution process using perovskite nanocrystals (PNCs) as emitting materials for light-emitting diodes (LEDs), solvent orthogonality typically plays a crucial role in preserving stable interfacial conditions between carrier transport layers on both sides. Unfortunately, there is lack of clear understanding which to choose and what effects has realizing photo/electroluminescence (PL EL) properties given PNCs. Here, we investigate impact merely changing dispersing solvents PNCs, belong...
Using time-resolved far-infrared spectroscopy, we observe multiple routes for photoinduced phase transitions in V(2)O(3). This includes (i) a photothermal antiferromagnetic to paramagnetic transition and (ii) an incipient strain-generated metal insulator transition, which manifests as coherent oscillations the conductivity. The ∼100 ps conductivity oscillation results from acoustic phonon modulation of bandwidth W. Our indicate that poor metals are particularly amenable strain control their...
HfSe2 field effect transistors are systematically studied in order to selectively tune their electrical properties by optimizing layer thickness and oxygen plasma treatment. The optimized plasma-treated showed a high on/off ratio improvement of four orders magnitude, from 27 105, mobility increase 2.16 3.04 cm2 V−1 s−1, subthreshold swing 30.6 4.8 V dec−1, positive threshold voltage shift between depletion mode enhancement mode, −7.02 11.5 V. photodetector also demonstrates reasonable...